Monthly Archives: January 2016

App note: Thermal behavior of small-signal discretes on multilayer PCBs

via Dangerous Prototypes

an_nxp_an11076

App note from NXP Semiconductors about multilayer PCB as additional heatsink for flat SMD components mostly power transistors to dissipate heat. Link here (PDF)

This application note illustrates how to improve the power dissipation of discrete components by using multilayer PCBs. It focuses on the impact of using larger copper areas to improve the thermal behavior of applications.

Free PCB Sunday: Pick your PCB

via Dangerous Prototypes

IRToy

We go through a lot of prototype PCBs, and end up with lots of extras that we’ll never use. Every Sunday we give away a few PCBs from one of our past or future projects, or a related prototype. Our PCBs are made through Seeed Studio’s Fusion board service. This week two random commenters will get a coupon code for the free PCB drawer tomorrow morning. Pick your own PCB. You get unlimited free PCBs now – finish one and we’ll send you another! Don’t forget there’s free PCBs three times every week:

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • Be sure to use a real e-mail in the address field so we can contact you with the coupon.
  • Limit one PCB per address per month please.
  • Like everything else on this site, PCBs are offered without warranty.
  • PCBs are scrap and have no value, due to limited supply it is not possible to replace a board lost in the post

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App note: Enhancing cellphone battery performance during GSM pulses through the use of a parallel supercapacitor

via Dangerous Prototypes

an_avx_EnhancingCellphoneBatteryPerformance

Low ESR and ESL supercapacitor paralleled to cellphone batteries can react more quickly to the demanding power required by GSM pulses. A great appnote read from AVX, link here (PDF)

With the constant addition of features and functionality, battery life and reliability are becoming increasingly vital to those who rely on their smartphones. The transmission signal requires quick pulses of current from the battery, potentially causing the instantaneous voltage of the battery to drop below the phone’s minimum voltage of operation. This may cause the power to the battery to be temporarily interrupted. A series of tests were performed on multiple battery chemistries to determine the beneficial effect of placing an AVX supercapacitor in parallel with the battery, to improve the life of the battery as well as the quality of power provided from it.

App note: QuickBoot method for FPGA design remote update

via Dangerous Prototypes

appps

A QuickBoot method for FPGA design remote update application note (PDF!) from Xilinx:

This application note presents detailed descriptions of the QuickBoot method that are important for evaluating the QuickBoot solution and debugging implementation problems. Demonstration implementations of the QuickBoot method are provided for the KC705 evaluation board using the serial peripheral interface (SPI) flash or byte-wide peripheral interface (BPI) flash. See KC705 Board Demonstrations, page 33 to run the QuickBoot demonstrations on the KC705 evaluation board.

App note: High voltage adjustable power supplies

via Dangerous Prototypes

 

app2

TI application note (PDF!) on high voltage adjustable power supplies:

An improved approach is shown in Figure 2. Here an LM329B 6.9V zener reference has been stacked in series
with the LM317’s internal reference. This both improves temperature stability, since the LM329B has a guaranteed TC of ±20 ppm/˚C, and improves regulation, because more loop gain is available from the LM317.
These techniques can be extended for higher output voltages and/or currents by either using better high voltage transistors or cascoding or paralleling (with appropriate emitter ballasting resistors) several transistors. The output short circuit current, determined by R3, must be within Q2’s safe area of operation so that secondary breakdown cannot occur.

ESP8266 Killer?

via hardware – Hackaday

We’ve seen rumors floating around the Twittersphere about a new integrated microprocessor and WiFi SOC: the NL6621 from Nufront. Details are still scarce, but that doesn’t seem to be because the chip is vaporware: you could buy modules on Taobao.com and eBay right now for between two-and-a-half and three bucks, and Nufront’s website says they’ve produced a million modules since 2013.

The NL6621 WiFi SOC is powered by a 160 MHz ARM Cortex-M3 with 448 KB of RAM, and everything else is integrated in the SOC. The module has 32 GPIOs, SPI, I2C, I2S digital audio, and most of the peripherals that you’d expect. They say they have a completely open source SDK, but we can’t find a link to it anywhere. An English-language forum has sprung up in anticipation of the next new thing, and they say that they’ve contacted Nufront about the SDK, so that’s probably as good a place as any to lurk around if you’re interested. With an ARM core, it shouldn’t be long before someone gets GCC working on these things anyway.

It’s also worth noting that we’ve announced ESP8266 killers before, and it hasn’t come to pass. The mixture of community and official support that (eventually) came out of Espressif seems to be the main factor determining the ESP8266’s success, and we don’t see that yet with the NL6621. So take the question mark in the title seriously, but if this turns out to be the next big thing, remember where you heard it first, ok?

Thanks [David Hunt] for the tip!


Filed under: hardware, news